From Food Network - http://www.foodnetwork.com/recipes/food-network-kitchen/french-macarons-3362691
Almond-Raspberry:
Tint the batter with 2 drops neon pink gel food coloring; flavor with almond extract. Fill with seedless raspberry jam (you'll need about 3/4 cup).
Mint-White Chocolate:
Tint the batter with 2 drops mint green gel food coloring; flavor with mint extract. For the filling, microwave 3 ounces chopped white chocolate, 2 tablespoons heavy cream and 1 tablespoon butter in 30-second intervals, stirring, until smooth. Stir in 1/4 teaspoon mint extract and 1 drop mint green gel food coloring.
Blueberry Cheesecake:
Tint the batter with 3 drops royal blue gel food coloring; flavor with vanilla extract. For the filling, mix 4 ounces softened cream cheese and 3 tablespoons blueberry jam.
Lavendar-Honey:
Tint the batter with 2 drops violet gel food coloring; flavor with almond or vanilla extract. For the filling, mix 3/4 cup mascarpone cheese, 2 tablespoons honey and 1 teaspoon ground dried lavender.
Pineapple:
Tint the batter with 2 drops lemon yellow gel food coloring; flavor with vanilla extract. For the filling, press 3/4 cup pineapple jam through a sieve, discarding any large pieces.
Other flavor ideas:
http://www.diys.com/french-macaroon-flavors/
http://www.indulgewithmimi.com/matcha-green-tea-macaron-recipe/